Yes, the exercise anecdotally served the purpose of improving his confidence. But no, your assumption that he would be unable to ask for a number he really wanted is unfounded and has nothing to do with your false analogy.
Also, asking for something you're not emotionally invested in has little bearing to asking for something you're emotionally invested in. As an example: Asking someone you only just met for their number bears little resemblance to asking a someone you really like to go for coffee or dinner with you... when you're emotionally invested, rejection stings.
Yes, the exercise anecdotally served the purpose of improving his confidence. But no, your assumption that he would be unable to ask for a number he really wanted is unfounded and has nothing to do with your false analogy.